Most of the present Liquid Crystal Displays (LCD) are the backlight type, which comprises a liquid crystal panel and a backlight module. The backlight module provides light source for the liquid crystal display panel for normally showing images. For making the outgoing light of the liquid crystal panel be the circularly polarized light, generally, the circular polarizers are respectively adhered on the upper surface and the lower surface of the liquid crystal panel.
In prior art, the circular polarizer can be obtained by stacking up one layer of ¼ wave plate on the linear polarization plate. The phase delay generates when the outgoing circularly polarized light passed through the ¼ wave plate. The optical efficiency Δn×d of the ¼ wave plate satisfies: as Δn×d=λ/4 (wherein d is the thickness of the ¼ wave plate, and Δn is the birefringence of the ¼ wave plate, and λ is the incident light wavelength); the outgoing light of the liquid crystal panel is the circularly polarized light. Because the change of Δn and the change of λ have no proportionate relationship, the visible lights of various wavelengths will not be circularly polarized light after passing through the ¼ wave plate, which will result in the issue of large view angle color washout.